Head for crimping metal caps on containers

ABSTRACT

The invention discloses a head for crimping metal caps on containers which have a neck provided with a crimping zone. The head includes a cylindrical casing having a ring mounted therein which is vertically displaced during crimping and returned by a spring. The ring has a sleeve portion provided with an internal crimping portion and an external guide rib which engages a contoured helical ramp means, the depth of which is constant and equal to the height of the rib over at least one revolution, and then progressively decreases.

tlnited States Patent [1 1 Vandrelneclr Oct. 115, 1974 [54] HEAD FOR CRIMPING METAL CAPS ()N 1,249,003 12/1917 Beyer 53/331 (:QNTAHNERS 3,757,487 9/1973 Fauth .1 53/334 lnventor: Roger Vandrebeclt, Saint-Swin sur Llsle, France Assignee: Cebal, Paris, France Filed: Nov. 23, 1973 Appl. No.: 418,261

Foreign Application Priority Data Nov. 27, 1972 France 72.42080 US. Cl. 53/331, 53/341 Int. Cl B67b 3/110, B67b 3/02, B67b 3/18 Field of Search 53/341, 343, 349, 331,

References Cited UNITED STATES PATENTS 6/1908 Weissenthanner 53/334 Primary Examiner-Travis S. McGehee Assistant Examiner-Horace M. Culver [57] ABSTRACT The invention discloses a head for crimping metal caps on containers which have a neck provided with a crimping zone.

The head includes a cylindrical casing having a ring mounted therein which is vertically displaced during crimping and returned by a spring. The ring has a sleeve portion provided with an internal crimping portion and an external guide rib which engages acontoured helical ramp means, the depth of which is constant and equal to the height of the rib over at least one revolution, and then progressively decreases.

3 Claims, 3 Drawing Figures PAIENIEBBETI'SIBN 3.841056 SHEEI 2 OF 3 Fig.2-

{115mm 1 sun SHEET 3 0F 3 Fig. 3

HEAD lFOR CRIMPING METAL CAPS ON CONTAINERS BACKGROUND OF THE INVENTION The present invention relates to a head for crimping metal caps onto containers having a neck provided with a zone to engage the caps, such as bottles, jars and flasks. A metal cap comprises a substantially flat end portion and a cylindrical or slightly frustoconical skirt portion. The function of the crimping head is to bend the metal of the skirt portion under the edge of the collar of the container, in order to produce an effective closure.

Prior crimping heads utilize either pinching or clamping means, or rotary serrated wheels. A crimping head with pinching or clamping means includes a carrier carrying fingers which surround the neck, and the lower end of which is inwardly curved. The fingers are urged outwardly by resilient means and are pressed inwardly by lowering a sleeve comprising a frustoconical ramp surface, the effect of which is to constrict the metal below the collar of the container neck.

These devices suffer from disadvantages resulting from the formation of folds in the skirt portion due to an excess amount of metal. These folds are displeasing in appearance and are often thecause of defective sealing of the container. In addition, when the containers provided with such caps are transported, the folds can cause the caps to hook up, resulting in caps being torn off.

Crimping heads employing serrated wheels use horizontal wheels which are carried by oscillating arms fixed on a rotary carrier. Lowering a ramp means which acts on the oscillating arms causes displacement of the serrated wheels in the direction of the neck of the container, and causes the metal to be constricted below the collar on the container neck. This head permits highquality stoppering of containers, but it is subject to a very high rate of wear, as it comprises many components which are either articulated or rotary and which wear rapidly. Moreover, the time required for maintaining the head and for replacement of the worn components is substantial and thus reduces the operating time.

It is accordingly an object of the present invention to provide a head for crimping metal caps on containers, which head remedies the above disadvantages. Other objects will be apparent from the following description.

SUMMARY OF THE INVENTION The head according to the present invention comprises a casing having a sleeve including a projection for holding a cap onto the neck of a container. The projection is surrounded by a crimping member, vertically displaceable and which is returned by a spring. The crimping member comprises a floating ring which has a sleeve carrying an external guide rib and an internal crimping ring portion, the internal diameter of which is slightly greater than the external diameter of the crimping zone on the container neck. The external guide rib tracks during crimping in a helical ramp means in the lower part of the internal wall of the casing. The depth of the ramp is constant and equal to the heightof the rib for at least one complete revolution. It then progres-. sively decreases. The width of the ramp is greater than the rib so that, when the projection carries the floating ring inwardly of the casing, the ring moves in a circle about the axis of the casing, remaining stationary however in the vertical direction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an axial cross-section of the crimping head prior to operation,

FIG. 2 shows an axial cross-section of operative engagement with the neck of a bottle,

FIG. 3 likewise shows the crimping head at the end of the crimping operation.

DETAILED DESCRIPTION In the drawings, the same components are denoted by the same references. The crimping head shown in the drawings may or may not be incorporated in an automatic processing train, or it may be used manually, for example, for capping short runs of bottles or for capping bottles of widely varying heights. In the latter case it is sufficient to provide the apparatus with an operating handle.

A casing 1 comprises an end wall portion and a cylin drical wall portion. Engaged in the casing is a hollow piston 2 having an internal recess 4 containing a coil spring 3 which bears against the internal wall surface of the end wall portion of the casing and against the piston. The end surface of the recess 4 carries a screwthreaded at 6, a rod 5 which passes through the end wall portion of the casing l. The rod 5 is slidable in the casing end wall portion, its movement restricted by a nut 7 which is screwed onto its free end.

A central plunger 8 is screwed at 9 into the end of the recess 4, in axial alignment with the rod 5. The plunger 8 is provided with a projection 10 which serves to hold the cap on the neck of the container during the crimping operation.

A floating ring 12 which, with the piston 2, is the only movable component of the apparatus, is positioned between the projection 10 and the external surface 11 of the end of the piston 2, and is slidable freely therebetween. The floating ring 12 comprises a flat end portion 13 provided with a central aperture 14 in which the central plunger 8 is engaged. The diameter of the central aperture 14 is slightly greater than that of the plunger. A sleeve portion 15 is perpendicular to the end portion 13 of the floating ring. The sleeve portion 15 is provided on its external surface with a horizontal guide rib 16 of rounded cross-section and, at the lower end of its internal surface, with a horizontal crimping ring portion 17.

Preferably the rib .16 and the ring portion 17 are formed as a single, removable ring member 18, which facilitates production and replacement thereof after wear. The ring member 18 is attached to the sleeve portion 15, for example, by means of screw members, the location of which bears reference: 19. The lower end of the ring member 18 can have an internal chamfer 20 in order to facilitate introducing the neck of the container.

The floating ring 12 is surrounded by a sleeve 21 which extends the cylindrical wall of the casing 1 in a downward direction. The sleeve 21 is secured to the casing 1, for example, by screw members having an axis 22. The internal wall of the sleeve 21 carries a ramp means 23 which is capable of receiving the rib 16, so

as to impart a downward helical movement to the floating ring 12 about the axis of the casing 1.

The ramp means 23 is in the form of a helix. Its depth is constant and equal to the height of the rib 16 for at least a complete revolution, it then progressively decreases over a fraction of a revolution until it completely disappears. The width of the ramp means is greater than that of the rib, its cross-section being widely open. Below the region occupied by the ramp means, the internal surface of the sleeve 21 comprises a cylindrical portion 26.

It is possible to provide the projection with a small magnet intended to retain the cap, in which case the caps must contain sufficient ferromagnetic material to be attracted by the magnet.

The sleeve 21 provided with the ramp means 23 has a particularly hard surface; in the apparatus described, by way of example, it is formed of steel covered with a hard chromium plating, but it can be of any other hard material such as a metal carbide. The removable ring member 18 constitutes the main component which is subject to wear; it must have a long life and have a low coefficient of friction. It can be made of a metal such as steel, or a plastics material, filled with graphite.

OPERATION The mode of operation of the apparatus will be described by reference to the operation of crimping a cap 25 onto a bottle 24 having a neck provided with a crimping zone 27. The cap 25 has a cylindrical skirt portion, the free end of which bears reference numeral 28.

The head receives the bottle having a cap resting thereon, the cap having been placed on the bottle neck at a prior working station.

Alternately, the head can receive the cap and the bottle separately. In this case the cap is fed by a special ramp means (not shown) into a position below the projection 10. The cap is then attracted to the projection 10 either by magnetic force, a vacuum suction force, or by a compressed air jet, and retained thereon either by magnetic attraction or by a vacuum applied through a vertical conduit in the projection 10 and the plunger 8. The bottle is then delivered separately to the head, and the bottle neck is placed in contact with the cap by bringing the crimping head and the bottle towards each other.

Crimping is effected by relative movement between the bottle and the head, and this movement can be achieved either by raising the bottle or by lowering the head. When the bottle 24 and cap 25 begin to bear against the projection 10 of the head, the piston 2 is raised, compressing the spring 3.

In a first phase, the rib 16 is guided by the cylindrical part 26 of the internal surface of the sleeve 21, so that the floating ring 12 is caused to rise vertically centered on the axis of the plunger 8.

When the rib 16 reaches the beginning of the ramp means 23, the floating ring 12 begins a lateral movement, and its axis departs from that of the casing. This movement continues for the time that the rib 16 is in contact with the portion of the ramp means 23 which is of varying depth. The floating ring continues its lat eral movement until the rib 16 engages the beginning of the part of the ramp means which is of constant and maximum depth. The distance of the axis of the ring12- from the axis of the casing 1 is then at its maximum and equal to the depth of the ramp means. The crimping ring portion 17 at one point thereof engages the bottle below the crimping zone 27, displacing the edge 28 of the skirt portion of the cap. The radial movement of the ring portion 17 and the rising movement of the ring 12 causes a crimping of the skirt below the zone 27.

In a third phase of the operation, the rib 16 is in point contact with the constant depth portion of the ramp means 23. The ring 12 then turns about the axis of the casing, while remaining at a constant distance therefrom. The rib 16 moves along ramp means 23, so that the crimping ring portion 17, which applies a radial pressure below the zone 27 of the bottle, also moves in a corresponding manner. Therefore, the edge 28 of the skirt portion of the cap is bent upwardly and pressed against the wall of the bottle below the zone, successively along the entire circumference thereof. This prevents the formation of folds. The ring portion 17 which is in contact with the metal thus makes a complete turn around the bottle for sealing the cap thereon.

A reverse movement whereby the crimping head and the capped bottle are moved away from each other causes the ring portion 17 again to apply pressure radially inwardly around the circumference of the cap. Finally the ring portion disengages the bottle. The piston 2 and the floating ring 12 return to their initial position under the action of the spring 3.

As an example only, the following figures indicate the essential dimensions of a crimping apparatus intended to crimp caps having a diameter of 37 mm.

The aperture of the movable ring at the height of the rib 16 is 37.5 mm. The first phase (ring centered) corresponds to a cylindrical portion 26 of 2 mm in height within the member 21 surrounding the floating ring 12. The second phase (moving the ring off-center) corresponds to a ramp surface of approximately extending over a height of 7 mm, the ramp surface arriving at a depth of 2.25 mm. Finally, for the third phase (crimping) the helical ramp means makes a turn of 360 with a rise of 14 mm. The spring 3 has a compression force of 300 decanewtons.

It has been found that in a single operation as described above, it is possible to crimp metal caps made of aluminum sheet which are 0.24 or 0.25 mm in thickness, one head being capable of capping 3,000 bottles per hour.

I claim:

1. A head for crimping metal caps onto containers having a neck provided with a crimping zone, said head comprising a casing in the form of a sleeve; a projection in the sleeve for holding the cap on the neck of the container, said projection being vertically displaceable, and returned by a spring; a floating ring surrounding the projection and carried therewith, said ring including a sleeve portion which carries an external annular guide rib and an internal crimping ring portion whose internal diameter is slightly greater than the external diameter of the crimping zone of the container, characterized by:

a helical ramp means in the lower part of the internal surface of the casing, the depth of said ramp means being constant and substantially equal to the height of the guide rib over at least one revolution, and then progressively decreasing, the width of said ramp means being greater than that of the rib, the rib being engaged at the moment of crimping in the ramp means such that, when the projection carries the floating ring inwardly of the casing, the ring moves in a circle about the axis of the casing, the ring remaining stationary in the vertical direction.

2. A head according to claim 1 wherein the floating ring comprises a flat end portion fixed on a sleeve portion and having a vertical aperture through which passes a plunger secured to a piston which is capable of vertical displacement in the casing, the piston being the axially directed surface of the sleeve portion. 

1. A head for crimping metal caps onto containers having a neck provided with a crimping zone, said head comprising a casing in the form of a sleeve; a projection in the sleeve for holding the cap on the neck of the container, said projection being vertically displaceable, and returned by a spring; a floating ring surrounding the projection and carried therewith, said ring including a sleeve portion which carries an external annular guide rib and an internal crimping ring portion whose internal diameter is slightly greater than the external diameter of the crimping zone of the container, characterized by: a helical ramp means in the lower part of the internal surface of the casing, the depth of said ramp means being constant and substantially equal to the height of the guide rib over at least one revolution, and then progressively decreasing, the width of said ramp means being greater than that of the rib, the rib being engaged at the moment of crimping in the ramp means such that, when the projection carries the floating ring inwardly of the casing, the ring moves in a circle about the axis of the casing, the ring remaining stationary in the vertical direction.
 2. A head according to claim 1 wherein the floating ring comprises a flat end portion fixed on a sleeve portion and having a vertical aperture through which passes a plunger secured to a piston which is capable of vertical displacement in the casing, the piston being urged downwardly by the spring, and carrying the projection therefor, characterized in that: the vertical aperture is of larger diameter than the plunger.
 3. A head according to claim 1, characterized in that: the external guide rib and the crimping ring portion are fixed on a removable ring member which is attached to the axially directed surface of the sleeve portion. 